ci: replace Travis with GitHub action

Author: nikku

.github/workflows/CI.yml

@@ -0,0 +1,23 @@
+name: CI
+on: [ push, pull_request ]
+jobs:
+  Build:
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        node-version: [ 20 ]
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+    - name: Use Node.js ${{matrix.node-version}}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{matrix.node-version}}
+        cache: 'npm'
+    - name: Install dependencies
+      run: npm ci
+    - name: Build
+      run: npm run all

.travis.yml

@@ -1,6 +1,6 @@
 # bpmn-js-differ
 
-[![Build Status](https://travis-ci.com/bpmn-io/bpmn-js-differ.svg?branch=master)](https://travis-ci.com/bpmn-io/bpmn-js-differ)
+[![CI](https://github.com/bpmn-io/bpmn-js-differ/actions/workflows/CI.yml/badge.svg)](https://github.com/bpmn-io/bpmn-js-differ/actions/workflows/CI.yml)
 
 A semantic diffing utility for BPMN 2.0 files. To be used together with [bpmn-moddle](https://github.com/bpmn-io/bpmn-moddle).